Merge pull request #10 from krakend/lru_http_cache

Add LRU cache option

.deepsource.toml

@@ -5,7 +5,7 @@ name = "go"
 enabled = true
 
   [analyzers.meta]
-  import_root = "github.com/krakendio/krakend-cors"
+  import_root = "github.com/krakendio/krakend-httpcache/v2"
 
 [[transformers]]
 name = "gofmt"

go.mod

@@ -1,8 +1,9 @@
 module github.com/krakendio/krakend-httpcache/v2
 
-go 1.17
+go 1.22
 
 require (
+	github.com/krakend/lru v0.0.0-20250121172718-0e3a6eab620d
 	github.com/krakendio/httpcache v0.0.0-20221129153752-65a87a5c2bc5
 	github.com/luraproject/lura/v2 v2.2.3
 )

go.sum

@@ -1,9 +1,9 @@
+github.com/krakend/lru v0.0.0-20250121172718-0e3a6eab620d h1:Kktd6hjWjY+TgL/oESBdTTVKJ7BFroS/YA2PZ1PsFLA=
+github.com/krakend/lru v0.0.0-20250121172718-0e3a6eab620d/go.mod h1:VgOve4vVYbY6UkD3qHdqmq2AKwqHlp39TKMi2b2cQBI=
 github.com/krakendio/flatmap v1.1.1 h1:rGBNVpBY0pMk6cLOwerVzoKY4HELnpu0xvqB231lOCQ=
 github.com/krakendio/flatmap v1.1.1/go.mod h1:KBuVkiH5BcBFRa5A1HdSHDn8a8LzsyRTKZArX0vqTbo=
 github.com/krakendio/httpcache v0.0.0-20221129153752-65a87a5c2bc5 h1:gB5divkol6FZK6OVGjh7odTsOY3FAESpeq9qyAVCZkc=
 github.com/krakendio/httpcache v0.0.0-20221129153752-65a87a5c2bc5/go.mod h1:VWTP3MZHr/W9OauBMrOQ2bD1rIjDetAQo5JbXCezYKE=
-github.com/luraproject/lura/v2 v2.0.5 h1:Mc4uj37s7mv6qRLy+Uo983CiaITPSVJYooeUilbiD+k=
-github.com/luraproject/lura/v2 v2.0.5/go.mod h1:r2N4j89Snm1j+Y9CCa9cYR1T2ETRL0E4y9P+DgymqX4=
 github.com/luraproject/lura/v2 v2.2.3 h1:zePcqPP7XXjDKmWht8hJbFoPVNtBgdV3I6F2PyTFaB8=
 github.com/luraproject/lura/v2 v2.2.3/go.mod h1:Outo/8O5zqa2itP1wD/mdD5nskjo09R74EbMVgr1L98=
 github.com/valyala/fastrand v1.1.0 h1:f+5HkLW4rsgzdNoleUOB69hyT9IlD2ZQh9GyDMfb5G8=

http.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"net/http"
 
+	"github.com/krakend/lru"
 	"github.com/krakendio/httpcache"
 
 	"github.com/luraproject/lura/v2/config"
@@ -32,19 +33,24 @@ func NewHTTPClient(cfg *config.Backend, nextF client.HTTPClientFactory) client.H
 		return nextF
 	}
 
-	var cache Cache
-
-	if b, err := json.Marshal(raw); err == nil {
-		var opts options
-		if err := json.Unmarshal(b, &opts); err == nil && opts.Shared {
-			cache = globalCache
-		}
+	b, err := json.Marshal(raw)
+	if err != nil {
+		return defaultClient(nextF)
 	}
 
-	if cache == nil {
-		cache = httpcache.NewMemoryCache()
+	var opts options
+	if err := json.Unmarshal(b, &opts); err != nil {
+		return defaultClient(nextF)
 	}
 
+	return getCachedClient(nextF, selectCache(opts))
+}
+
+func defaultClient(nextF client.HTTPClientFactory) client.HTTPClientFactory {
+	return getCachedClient(nextF, httpcache.NewMemoryCache())
+}
+
+func getCachedClient(nextF client.HTTPClientFactory, cache Cache) client.HTTPClientFactory {
 	return func(ctx context.Context) *http.Client {
 		httpClient := nextF(ctx)
 		return &http.Client{
@@ -59,8 +65,32 @@ func NewHTTPClient(cfg *config.Backend, nextF client.HTTPClientFactory) client.H
 	}
 }
 
-var globalCache = httpcache.NewMemoryCache()
+func selectCache(opts options) Cache {
+	if opts.MaxSize == 0 || opts.MaxItems == 0 {
+		if opts.Shared {
+			return globalCache
+		}
+		return httpcache.NewMemoryCache()
+	}
+
+	if !opts.Shared {
+		cache, _ := lru.NewLruCache(opts.MaxSize, opts.MaxItems)
+		return cache
+	}
+
+	if globalLruCache == nil {
+		globalLruCache, _ = lru.NewLruCache(opts.MaxSize, opts.MaxItems)
+	}
+	return globalLruCache
+}
+
+var (
+	globalLruCache Cache
+	globalCache    = httpcache.NewMemoryCache()
+)
 
 type options struct {
-	Shared bool `json:"shared"`
+	Shared   bool   `json:"shared"`
+	MaxSize  uint64 `json:"max_size"`
+	MaxItems uint64 `json:"max_items"`
 }